System and methods for monitoring caregiver performance

ABSTRACT

Systems and methods for monitoring the performance of a caregiver are disclosed. The systems may be configured to monitor the movement of each subject in a network of subjects. One such system includes a plurality of strips adhered in spaced-apart relation on a mattress pad, upon which a subject is positioned. One or more transmitter is provided coupled to the plurality of strips. A processor is connected to the one or more transmitter. The processor is provided with operating software to record and report caregiver activity or both caregiver activity and subject activity.

PRIORITY STATEMENT

This continuing patent application claims the benefit of Non-ProvisionalU.S. patent application Ser. No. 11/133,405 filed May 19, 2005, now U.S.Pat. No. 7,541,935.

FIELD OF THE INVENTION

The present invention relates to systems and methods for monitoringsubjects, such as human subjects. More particularly, the presentinvention relates to systems and methods for monitoring and reportingcaregiver performance in a healthcare setting related to care of asubject on a subject support device, such as on a hospital bed ornursing home bed.

BACKGROUND OF THE INVENTION

Many subjects in nursing homes may not have the physical capability toturn or reposition themselves in a bed and in such a case, depend uponstaff members, typically a Certified Nursing Assistant (CNA) or othercaregiver, to move them. This scenario may also occur in a hospital orsimilar setting. In many instances, it is a requirement or medicalnecessity that the subject be turned in bed frequently, at a specifiedinterval, such as for example, every two hours, to prevent thedevelopment of tissue or skin breakdown, which can severely compromisehealth, comfort, and quality of life. Failure to periodically move thesubject can result in what is commonly known as pressure sores or“bedsores”.

What is needed is a system and method that can monitor the movement of asubject, patient or resident, (hereinafter referred to simply as“subject”) so that movement of the subject can be detected, tracked,recorded and reported. Accordingly, systems have become available whichalert a caregiver when a subject has moved or left the bed. Some ofthese systems have sophisticated means of determining the position ofthe subject on the bed. As used herein, the terms “CNA”and “caregiver”are used interchangeably and refer to a person providing care to anindividual subject or subjects. Such a system and method may be used tomonitor when a subject leaves and returns to the bed and detect andmonitor patterns of movement. In many cases, subjects are unable tostand or walk from their bed unaided; however, these subjects attempt toexit their bed in a weakened condition and are at risk of falling andassociated injuries. The system has the inherent ability to provide asignal when a subject has exited their bed and will notify theresponsible caregiver of this situation.

These systems do not have a means to allow nursing home administrators,hospital supervisors or healthcare managers (hereinafter referred to as“clients”) to confirm that a CNA or the like has performed his or herduty to move the monitored subject. The present invention addresses thisneed.

SUMMARY OF THE INVENTION

The present invention is directed to systems and methods for monitoringthe performance of a caregiver. Simultaneously, the present invention isdirected to systems and methods for monitoring the movement of eachsubject in a network of subjects and the response of the caregiver.

One system is shown to include a plurality of sensors, preferably in theform of strips disposed in spaced-apart relation to a mattress pad. Thestrips extend longitudinally from the head end of the mattress pad. Themattress pad is configured to be placed on top of a mattress, and tothen be covered by a standard nylon slip-cover or the like that fitsover the mattress and the mattress pad.

All software aspects of the invention have been written to be portableto multiple operating systems and hardware platforms. Open sourceapplications and development tools have been used to limit downstreamsystem, licensing and development costs. Web browser based data entryand reporting systems have been used to reduce client costs and allowusers to interact with the system on familiar interfaces and hardware.It also allows handheld devices, pagers, cell phones, tablet PCs, etc.to be used without additional software development costs. Raw data isalways stored so future enhanced data analysis tools have access to theoriginal data. Multiple levels of security are used to protect theintegrity and confidentiality of the data.

This system may include hardware and functionality in order to functionas a bedside based undergarment moisture detector. In such a case,transmission of moisture data from patient undergarment to bedside wouldbe performed via Wireless link such as RFID, ZigBee™, IR, Bluetooth™,etc. A small probe, such as a very thin wire is penetrated through theouter plastic surface into absorbency material. The probe could bedesigned to penetrate the backside of undergarment and be positionedwhere it could detect moisture. A very thin wire could run from thesensor to a small transmitter which would be attached to the frontundergarment waistline of the subject. This front side transmitter couldbe a low cost, high efficiency, reusable transmitter which would enabledata to be transmitted area wide or to the bedside DCT. At apredetermined value, the CNA could be notified that the subject was inneed of an undergarment change. The major advantage that the CNA wouldno longer need to perform periodic checks, but only when specificallyneeded.

A nurse call module is provided and is adapted to be used as a deviceable to detect when a nurse call is placed on a conventional system andwhen it is answered. As the call is placed, the inline module detects anurse call signal and then independently sends this signal back to thebedside DCT which then transmits it to the central processor where it istime and date stamped, and then incorporated into the database relativeto the patient and/or DCT ID. In addition to the conventional audio andvisual signals generated during a nurse call, the system also pages,emails or notifies via mobile phone that a subject is in need ofassistance. Once the care has been rendered, the CNA would switch offthe bedside nurse call device which would also signal the centralprocessor to stamp the database with a time and date. The proposeddevice would be an in-line component which would be “jacked” into thewall and then the nurse call connector would be snapped into thisdevice. The central processor could communicate to the DCT or other typeof bedside transmitter via a hard wire or wireless connection. The majoradvantage of the system of the present invention is that the existingnurse call system would perform as intended, with the added advantage ofverifiable care giver performance response time, thus allowing a bettermethod of caregiver quality control.

A proposed system could also act as a bed alarm, monitoring when the bedis occupied or when it is empty, thus allowing the caregiver to benotified when a high risk “fall” subject is out of bed and in danger offalling while unattended. This warning system could be linked to theexisting in-house audio and visual indicators as well as nurse stationcomputer screen notification in addition to mobile phone, pager andother communication systems.

The DCT has an excess of bandwidth in both its wireless and hardwiredconfigurations. This additional capacity combined with its currentfunction as a bedside data collection and transmission device providestremendous opportunities for additional in-room capabilities. Some ofthese concepts include voice, data and video communication, including aroom call and patient audio and video monitoring. Other capabilitiesinclude high bandwidth devices such as sensors or monitors plus in-roominternet connectivity.

Additional features of the invention will become apparent to thoseskilled in the art upon consideration of the following detaileddescription of preferred embodiments exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a schematic view of the monitoring system;

FIG. 2 is a cutaway perspective view of the head end of a mattress padwith sensors according to an embodiment of the invention;

FIG. 3 is a top plan view of the mattress pad and sensors;

FIG. 4 is an elevation view of the mattress pad;

FIG. 5 is a top plan view of a mattress pad and sensors covered by amattress cover according to another embodiment of the present invention;

FIG. 6 is an elevation view of the mattress pad of FIG. 5 and amattress, both of which are covered by a mattress cover;

FIG. 7 is a cutaway view of part of FIG. 5, showing the mattress,mattress pad, and fastener, all of which are covered by the mattresscover;

FIGS. 8-12 each show a subset of operational steps of a data collectortransmitter and the software therefor according to a method of operationof the present invention;

FIGS. 13-20 each show a subset of operational steps of the data serversoftware according to a method of operation of the present invention;

FIG. 21 shows a “Home Page” according to an embodiment of the presentinvention;

FIG. 22 shows a “24 Hour Facility Activity Report Page” according to anembodiment of the present invention;

FIG. 23 shows a “View Room Groups Page” according to an embodiment ofthe present invention;

FIG. 24 shows a “Patient Reports Page” according to an embodiment of thepresent invention;

FIG. 25 shows a “Monitor Reports Page” according to an embodiment of thepresent invention;

FIG. 26 shows a “Room Status Reports Page” according to an embodiment ofthe present invention;

FIG. 27 shows a “Patient Administration Entry Form Page” according to anembodiment of the present invention;

FIG. 28 shows a “New Bed Monitor Entry Form Page” according to anembodiment of the present invention;

FIG. 29 shows an “Edit Room Groups Form Page” according to an embodimentof the present invention; and

FIG. 30 shows an “Edit Room Administration Page” according to anembodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

A system 31 for monitoring the performance of a caregiver relative tomovement of a single subject 32 or a plurality of subjects 32 is shownin FIG. 1. Illustratively, subject 32 is positioned on a bed 34, but itshould be understood that other subject support devices, such as chairs,wheelchairs, or the like, are within the scope of the invention.Accordingly, all of the attributes of the system 31 described herein canbe applied to any type of subject support device.

As shown in FIG. 1, system 31 includes a plurality of beds 34, eachhaving a sensor 36 that is in communication with a central processor 38,such as that which can be found in the computer shown in FIG. 1. Thesensor 36 may be a single sensor or preferably a sensor array includinga plurality of individual or separate sensor units. The centralprocessor 38 may take the form of other computing devices having thecapability of detecting changes in the status of sensors 36 andoutputting an alarm, notice or report, for example. The system 31preferably uses a web browser based reporting system. Reports aregenerated on a web server (not shown) and viewed on standard webbrowsers with no special software required. The data is presented in ahierarchical fashion giving a quick overview as well as the ability todrill down to the lowest level of interest. The reporting system isdesigned to quickly identify areas of the facility that may needattention. Other functions—such as a data gathering device—of thecentral processor 38 will be explained in more detail below.

The sensors 36 may include electrically conductive strips, which whenthey are brought into proximity or are permitted to disconnect, undergoa change of state with respect to, for example, opening or closing acircuit.

Other sensors are also contemplated that are capable of sensing a changeof position or status of a subject, such as pressure sensors, heatsensors, and so on. The sensors 36 may include conductive material, suchas conductive paint, plastic, metal or any other material that whentriggered functions to register or detect a change of status of asubject operatively associated with the sensor and generate or permitthe generation of a signal or event therefor.

Sensors 36 may communicate with central processor 38 via a wireless(WiFi) connection. Transmitter 40 is shown as a wireless transmitterwhereas transmitter 46 is shown as a wired transmitter that bothcommunicate with a base station 42 that is connected with centralprocessor 38. The transmitters, both shown at 40 and 46, and based on aMotorola IC, part no. 33794, are also referred to herein as a datacollector transmitter (DCT) unit, which is a slave device that transmitsdata to a master device (referred to herein as the central processor 38)using a predefined protocol. The protocol is designed to be compatiblewith a wide range of networks including, but not limited to RS232,multi-drop RS485 as well as higher level networks such as Ethernet,Bluetooth™, ZigBee™, 802.15.4 and WiFi. Addressing and error detectionis provided at the lowest level of the protocol for use on simple RS485type networks.

The central processor 38 collects data from the slave DCT units 40, 46.The central processor 38 requests data from each DCT unit 40, 46 at thedesired data rate. Preferably, the data processor 38 is a networked PCrunning applications designed to communicate with as many as severalhundred DCT units 40, 46 at the same time. It is a multi-threaded,object oriented, fault tolerant program that can recover from networkand DCT units 40, 46 problems in real time without affecting datagathering on the rest of the system 31. The central processor 38 maystore all data into a standard SQL relational database 39.

The central processor 38 may be a standard PC running a Javaapplication. The program reads and writes to a database 39. The centralprocessor 38 uses conventional programming to interface with thedatabase 39, so portability to other databases is possible. The centralprocessor 38 polls the database 39 at regular intervals to determine thenumber of clients (DCT units or installations) it needs to communicatewith. Each DCT unit 40, 46 has a unique address and communication ratestored in the database 39. The device and the applications runningthereon are multi-threaded so problems with individual devices andnetwork latency do not affect other devices and program performance. Ifone transmitter 40, 46 is not responding, all other devices will stillreturn data at the predetermined rate. The central processor 38 willcontinue to try to regain communication with the non-responsive slaveuntil it is successful or the entry in the database is removed. The datareceived from the transmitters 40, 46 is stored in the database 39. Thedata is time stamped and referenced to the transmitters 40, 46. Toreduce the database growth, if there is no movement by the subject, orif the subject is no longer in bed, the recorded sensor values will beat wider intervals. However, once movement is again detected, the systemwill be triggered to begin collecting data at a more rapid andpredetermined pace allowing full resolution of the subject movement.Even if the minimum change amount has not occurred, data will at leastbe stored at a predetermined interval such as once every 10 seconds, forexample, or at any suitable interval. The central processor 38 isintended to run autonomously.

The sensor 36 is connected to the DCT 46, which includes amicrocontroller. The microcontroller has custom software written in theC programming language. The microcontroller constantly polls the sensor36 looping between the 9 electrodes of the sensor 36 using one ofseveral built in 10-bit analog to digital channels. The microcontrollercan calibrate the system to adjust the output of the electrodes so theyall read roughly the same value when no subject 32 is in the bed 34. Itcan also adjust the high and low end points of the sensor values to usethe full 10-bit range. The calibration values are stored in non-volatileEEPROM so they are not lost if the power is interrupted or removed. Theread values are adjusted by the stored calibration and stored in RAM.The values in RAM are then used to quickly respond to the master devicewhen requested.

All communication is done with the microcontroller using a serial dataprotocol. The protocol uses an 8-bit address and a 16-bit CRC to insuredata integrity. While the address and CRC are not needed withhigher-level networks like Ethernet, they allow the use of future,simpler networks like RS485. The DCT units 40, 46 currently uses an OEMserial to Ethernet device (not shown), but another embodiment includesintegration into the microcontroller.

Although wireless transmitters 40 are shown in FIG. 1 to be separatefrom sensors 36, and connected with a harness 44, it is within the scopeof the invention to combine the wireless transmitter 40 with the sensoror to place it in other locations, such as within a bed mattress.Wireless transmitters 40 are illustratively capable of collecting datafrom their associated sensors 36. The system 31 is preferably configuredso as to be capable of handling upwards of a hundred beds or more thatmay comprise a hospital network or a nursing home network, for example.

As an alternative, a transmitter 46 may be used, the transmitter 46having a wired (e.g., Ethernet) connection with central processor 38.Illustratively, transmitter 46 uses an Ethernet network consisting ofEthernet cables and an Ethernet hub 50 that is in communication withcentral processor 38. Of course, system 31 may include both wireless andEthernet elements, and may be connected via other means and/orprotocols, such as coaxial cable, electrical wires, radio frequency,Bluetooth™, ZigBee™, 802.15.4 or any other manner for communicating datathat is known in the art.

As can be seen in FIGS. 2-7, sensor 36 comprises a mattress pad 54having an array of parallel conductive fabric strips 58 adhered thereto.Strips 58 extend longitudinally along the mattress pad 54, starting atthe head end 60. A fastener 52 may be coupled to one end of each of thestrips 58 at the head end 60 of the mattress pad 54. While theillustrated embodiment contemplates the adhesion of the strips 58 to anupper surface or top side 64 of the mattress pad 54, it should beunderstood that other configurations and fastening methods are withinthe scope of the invention, including the placement of the strips 58within the pad 54, or on top of another surface such as directly on topof a mattress 56.

In the illustrated embodiment, strips 58 are evenly spaced at aninterval A (shown in FIG. 3), such as four inches. Strips 58 areillustratively width B, which is approximately one inch in the presentlyshown embodiment.

Mattress pad 54 is illustratively a half-inch thick urethane foam padthat is cut to the same dimensions as a mattress 56 on which it is to bepositioned. Such urethane foam is flame retardant, thereby meeting theFF 4-72 (cigarette test) standards for flammability set forth by theConsumer Product Safety Commission. Furthermore, the foam preferablyconforms to the California Technical Information Bulletin No. 117regarding combustibility.

In the illustrated embodiment, nine strips 58 are positioned in parallelorientation to run longitudinally from the head end 60 of mattress pad54. Each of the strips has an adhesive bottom surface (not shown) thatis configured to adhere to the mattress pad 54. The adhesive surface isillustratively a pressure sensitive adhesive (PSA), however, otheradhesives are within the scope of this invention. After each of thestrips 58 is adhered to a top side 64 of the mattress pad 54, the entiremattress pad is overlaid with a flame retardant polyester cloth 55,(FIG. 7) thereby capturing the strips 58 and functioning so that thestrips remain securely in place throughout the life of the mattress pad54.

Strips 58 may be any suitable thickness, such as approximately 0.008inches thick and made of a conductive laminated fabric. The laminatedfabric is flame retardant with a UL 94 V-0 rating. One example of such afabric is manufactured by Laird Technologies of St. Louis, Mo.

As can best be seen in FIGS. 5-7, which shows another embodiment of aportion of the present invention, an outer mattress cover 62 ispositioned over mattress 56 and overlying mattress pad 54 so that theentire sensor 36 is removed from direct contact with sheets or asubject. Mattress cover 62 is preferably a standard nylon covering usedover a standard nursing home mattress.

As can be seen in FIGS. 2, 3, and 7, a fastener 52 is pressed into eachof the strips 58, providing an electrical connection therewith. Fastener52 may be a male metallic snap fastener that functions as the connectionpoint between the conductive fabric strips 58 and a connector harness44.

The connector harness 44 links the array of strips 58 to either awireless transmitter 40 or a standard, wired transmitter 46 (FIG. 1). Asmentioned above, the transmitters 40, 46 function as a data collectorand a transmitter of such data. In one embodiment, the harness 44 mayinclude nine coaxial conductors approximately 30 inches in length. Eachof the individual coaxial conductors is approximately ⅛ inch indiameter. At the end proximal to the mattress pad 54, each of thecoaxial connectors is terminated by a ⅛ inch crimp-on ring terminal,which allows simple and secure attachment to the array of stripsutilizing the female snap ring to capture the ring connector (notshown).

The end (not shown) of the harness 44 which attaches to the transmitter40, 46 may include a D-Sub 15-pin male connector. Each of the ninecoaxial center leads (not shown) may be individually crimped into aconnector pin and inserted into locations within the connector backshell. Each of the nine outer shields from each coaxial conductor may besoldered with a “drain wire” or alternately, stripped and combined intoa single termination which may be soldered together to ensure propertermination, and covered with a heat-shrink insulator. All nine drainwires may then be combined into a single conductor and crimped into theconductor as a tenth pin connector. Through the use of coaxialconductors, signal integrity to and from the array of strips 58 tend tobe consistent and reliable during operation. The back shell (not shown)also permits the ability to monitor and verify whether the connector issecurely attached to the transmitter 40, 46. A wire loop (not shown) canbe configured to connect to two specific pins within the back shell.Alternately, a single wire may be used with the actual metallic backshell, used as the other conductor, and acting as a complete circuitwhen connected. When the wire completes the simple circuit within thetransmitter 40, 46, the electronic circuitry will indicate that allsystems are functional. Should the connector unfasten from the back ofthe transmitter 40, 46 the circuit will be broken, which willimmediately flag the system 31, advising that the connection between thearray of strips 58 and the transmitter 40 (or 46) has been broken.

The transmitters 40, 46 utilize electrical-field sensing technologycombined with a programmable microcontroller that acts as the computingportion of system 31. The transmitter 40, 46 performs multiple functionsby communicating with the array of sensors 36 and then transmitting thisinformation to a remote database 39 (FIG. 1) for interpretation andreview. The database 39 stores data for the facility, room groupings(wings, floor, building, etc.), rooms, and subjects 32. The database 39also stores addressing and configuration information for the DCT units40, 46. Finally, the database 39 also stores all of the loggedinformation from the DCT units 40, 46.

The database 39 also stores other data related to the installationfacility. This allows data to be correlated to the facility, facilityzones, caregivers and subjects. The facility information is entered intothe system 31 using a web browser. The interface is designed to allowvery efficient data entry.

Each DCT 40, 46 generates a unique electrical-field to each of the ninestrips 58 within the array of strips. As each of these strips 58 areenergized with a very low electrical-field, within milliseconds, aunique signal is returned relative to the size and position of thesubject 32 above the strip 58. In the present embodiment, this isperformed continuously across all nine strips 58, taking full positionalinformation twice every second. Any change in the position of thesubject 32 generates a change in the electrical-field of the array ofstrips 58. Other schemes are also contemplated, such that sufficientinformation is collected to detect movement of the subject 32.

Once a transmitter 40, 46 has received the information from the array ofstrips 58, the information is converted into a digital code and sent vianetwork to the central processor 38 (FIG. 1) for inclusion into adatabase 39 (FIG. 1) correlated to specific bed information, along witha time and date stamp. The transmitter 40, 46 is designed to be flexiblein its data transmission mode and can be utilized in a hard wired orwireless network mode, as disclosed above.

Each transmitter 40, 46 can be powered by a 12-volt wall-mounted powersupply capable of a maximum 500 milliamp current draw. Alternately, itis envisioned that an internal power source could be utilized in lieu ofan external power source. Examples include lead acid, NiMH, and fuelcell type power sources. The transmitter 40, 46 also incorporates asolid state, resettable fuse insuring that the current will be cut offshould there be any reason that current is drawn above the requiredpower draw for the device. The housing for the transmitter may be formedby injection molding with ABS plastic having a flame retardant rating ofUL94 V0.

Ethernet hub 50 can be a standard 10/100 hub that can be found at anycomputer or electronics store. Base station 42 can also be a standardwireless/hard-wired base station that can communicate, for example, overthe 802.11 standard for wireless communications. It should beunderstood, however, that other configurations are within the scope ofthe invention, for example, base station 42 and Ethernet hub 50 could becombined into one device. System 31 can be configured to notify selectedpersons, i.e. nursing home or hospital management, via pagers 53, cellphones 51, e-mail 49, (see FIG. 1), fax, etc. through the Internet 47,wired or wireless or any suitable communication means or method.

System 31 can also be connected to the Internet 47 (FIG. 1) to permitremote access via either an in-house web page or a secure connectionutilizing a standard web browser. The client interface may be entirelyweb browser based. The web pages may be served from a Windows InternetInformation Server (IIS) using the PHP scripting language. The clientscan see the data as pure standards based HTML without any specialapplications or plug-ins required. This allows any browser and operatingsystem to access the system. Varying levels of access can be granted foraccess to the data stored by the system 31.

A software program manages the microcontroller, providing control of theelectrical-field. It also routes the data out of the transmitter 40, 46and into the network.

The central processor 38 functions in at least two capacities: datagathering into a database 39 (FIG. 1) stored in or in communication withcentral processor 38, and data interpretation and report generation. Asmentioned above and discussed in further detail below, it is alsocontemplated that data interpretation and report generation may beperformed by a web server.

The database 39 can track the data from each of the transmitters 40, 46on a continuous basis. In the present embodiment, information from eachstrip 58 in the array of strips is stored and time stamped twice everysecond. The database 39 then stores the information and can group theinformation, for example, to track: (a) unique bed, floor/wing, andfacility information relative to a caregiver's responsibility, (b)individual subject position data as a function of time, (c) transmitterinformation relating to IT addresses and other hardware characteristics,and (d) facility names and other identifiable characteristics.

The database 39 stores data from each transmitter 40, 46, which can betime-stamped for analysis and interpretation. Through the use of dataanalysis processes executed by software (detailed below) meaningfulindicators can be established to confirm caregiver activity and theassociated subject movement relative to specified medical orders. Theoutput data may be selectable so as to provide a morning report giving abrief overview of caregiver performance on targeted subject rotations.Additionally, weekly and monthly performance reports may be created andcan again be arranged by a particular caregiver.

In operation, the system 31 may be used as follows. A facility managermay review a status report displayed on or printed through centralprocessor 38 upon his/her arrival at the beginning of the shift. Such astatus report could show the performance of caregivers on the priorshift, as well as any movement of the subject 32. The report couldcorrelate movement or caregiver-initiated movement with that ordered bya physician. Other reports may be executed that show movement over alonger period of time, or even that show performance of a particularcaregiver over a period of time. Results could also be color coded,could be arranged by building wings or groups of rooms, or arranged inany other manner that is intuitive or preferred to the management.Information could be password protected in order to prevent the breachof security.

It is an advantage of the system 31 that no direct subject contact needoccur and the system is nearly completely out of sight from the subject32. In the event that the system 31 is disabled or switched off, noadverse side effects will occur since the system is not attached to thesubject 32. Furthermore, the immediate health of the subject 32 is notdependent upon the operation of the system 31.

FIG. 8 shows the initialization sequence of the data collectortransmitter (DCT). The DCT is powered on 102. The hardware portion ofthe DCT is initialized 104 and an indicator, such as an LED is used toindicate start-up, preferably by blinking on and off or by displaying apredetermined first color 106. Interrupts and timers are enabled 108.Configuration and calibration data is read 110, preferably off of anon-volatile device, such as non-volatile EEPROM. Variables areinitialized and the first sensor is selected 112. The program thenenters an infinite loop of reading the sensors in sequential order. Theprocess waits a predetermined amount of time while the sensor settles114. At step 116, the DCT begins to read the sensor. The microprocessorwill generate an interrupt when the analog to digital conversion iscomplete. Before the process loops back to step 114, it checks to see ifa completed calibration needs to be saved 118. If necessary, calibrationis saved at step 120. When an analog to digital conversion completes, aninterrupt occurs at step 162 (FIG. 12) and the value is saved to RAM164. At this time, calibration calculation and/or digital filtering mayoccur, depending on the current mode of operation. The current sensornumber is then indexed 166 to the next number. The sensor index iscompared to the maximum sensor index 168. If the sensor index is greaterthan the maximum sensor index the sensor index is set to the sensorminimum 170. The interrupt exits at step 172.

The serial data receive process is also interrupt based (FIG. 9). Aninterrupt is generated for each character received 122. A communicationtimer is restarted 124. The buffer index is incremented 126 and acharacter is gotten 128. The character is analyzed to determine if it isthe first byte 130. If it is, the character is subsequently analyzed todetermine if it is the header byte 132, if it is the header byte theinterrupt exits 136. If at step 132 the character is determined not tobe the header byte the buffer index is reset to zero 134 and theinterrupt handler exits 136. More specifically, the timer interruptoccurs 156 after the receipt of each character to clear the buffer 158if partial messages or erroneous data are received (FIG. 11). Theinterrupt exits at step 160.

Going back to step 130 if the character is determined not to be thefirst byte, a determination of whether the index is greater than thelength character and whether all the characters are present is made 138.If the determination at step 130 is answered in the affirmative, theprocess proceeds to step 142 if not the process proceeds to step 140. Atstep 140 it is determined whether the buffer is full, if it is thebuffer index is reset to zero 134 and the interrupt handler exits 136.If the buffer is not full the buffer index is incremented 146 and theinterrupt handler exits 136. At step 142 it is determined whether theCRC (Cyclic Redundancy Check) is correct, if it is, the DCT processesthe command and the response is returned 144 and the interrupt handlersubsequently exits 136. If at step 142 the CRC is found not to becorrect, the buffer index is reset to zero 134 and the interrupt handlerexits 136.

A general purpose timer (FIG. 10) also generates an interrupt on aperiodic basis. On each of these interrupts 148, the DCT does a generalstatus check to determine if any problems have occurred; such as sensorcable disconnection 150 or other communications errors. The fault LEDwill toggle state 152 at this time if a fault exists. If no problemshave occurred the general purpose timer exits 154.

FIG. 13 shows the startup sequence of the data server. After startup174, the graphical interface is initialized 176, and then a “collection”is created 178 to track the active slave devices (DCTs). A timer isstarted 179 that will periodically check the database to determine ifnew DCTs need to be added to the collection or if any need to beremoved. The program startup is complete at step 180.

When the DCT check timer event occurs at step 182, (FIG. 14) the activeDCT list is read from the database. Records of active DCTs are assembledinto a recordset at step 184. The program iterates through the recordsat steps 186-192 to determine if any DCTs are new or need to be removed.More specifically, a record in the recordset is selected at step 186. Atstep 188, it is determined whether a corresponding object exists for therecord. If no such object exists one is created at step 190. Once anobject exists for the record, it is determined whether there are anyadditional records at step 192. If there is at least one such additionalrecord, the program returns to step 186. If no such additional recordsexist at step 192, objects corresponding to non-active DCTs are removedat step 194. The timer hander exists at 196.

Each DCT is communicated with using its own program thread (FIG. 17).This prevents problems with other DCTs from affecting communication withother DCTs. At the creation of each thread 206, a log interval timer isset up 208. A network connection is then attempted to be established210. This will loop forever until a connection is established 212 or thethread is terminated. The main server thread is informed of the currentconnection status of each thread 214, 216. If a connection isestablished, the log interval timer is then started 218 and the processexits 220.

When a log timer event occurs 222, a message is sent 224 to the DCTrequesting current sensor values as shown in FIG. 18. The thread willthen wait until the data received event occurs at step 242 (FIG. 20).The message will be verified for integrity 244. If integrity is notpresent, the response is ignored 246. Valid data messages will generatean event 250 for the main server thread (FIG. 15).

When DCT data received events occur at step 198, (FIG. 15) the serverstores the data in the database, time stamped and tagged to the patient200. When DCT threads detect a change in status of the DCT 202, it willgenerate a status change event 204 (FIG. 16). When these events occur,the main server thread updates the interface and writes to the database.

Shown in FIG. 19, when a status-change event occurs, the event handlerstarts at 228. Once started, the event handler sends the event and itsstatus to the parent 230. The event handler then exits at 240.

The system 31 user software is preferably designed to operate as a webbased system with the functionality of being easily accessed on-site orfrom a remote location using a standard web browser, e.g., MicrosoftInternet Explorer™ or an equivalent thereof. The browser enabledinterface (see FIG. 21) is designed to operate independently from allother software elements within the system 31, including the “bed logs”database 39 and data collection from sensors 36, and DCTs 40, 46portions of the overall system. The “Home Page” 300, shown in FIG. 21,is also the main screen which all users will first encounter wheninterfacing with the system 31.

The home page 300 is broken out into two main sections, a reportgenerating portion 302 and administrative portion 304 including patient,monitor and room information. All of these individual sections may bepassword protected depending on the pre-determined authorization of theend-user. At any time within the various sub-menus, the logo 306 may beclicked which will take the user back to the home page 300.

An objective of the system 31 is to insure that while a patient is underthe care of a healthcare professional; all rotations are performed atthe specified intervals as dictated by medical orders. The system 31will continuously provide critical caregiver performance data detailingthe type of movement performed and most importantly time and date ofthese interactions insuring that a formal record of performance isestablished.

The “24 Hour Facility Activity Report,” 310, FIG. 22, is intended to actas a quick facility scorecard, which will visually indicate overallperformance of all assigned caregivers, relative to all rotationsrequired throughout the entire facility duty shift. This record will betypically reviewed by a manager or supervisor at the end of a facilityshift. Although the report described is based on a 24 hour duty cycle,additional reports will include other durations including real-timeinformation, weekly or monthly performance indicators.

Three simple visual indicators 312 will show green, yellow or red, forexample, describing level of performance within the facility. If theindicator is green, this may confirm that all rotations within thefacility were performed according to specified medical orders. If theindicator is yellow, this may mean “caution” which points to the factthat specific patients may not have been rotated as required by medicalorders and/or at the specified times. Additional investigation may berequired to determine what had transpired during the interval underquestion. The red indicator may specify that there may have beensignificant portions of the patient rotation regimen not completed. Nearthe bottom of the page 314, the end user can click on the “View RoomGroups” to drill down further into caregiver performance data relativeto individual caregivers on specific floors or facility wings.

The View Room Groups screen 320 (FIG. 23) is designed to show roomgroupings within a facility, which are typically tied to a specificcaregiver during their duty shift. This information will allow facilitymanagement to determine which specific rooms, beds and the specificpatients that were not rotated during a set period of time.

The Patient, Monitor and Room Status Reports, 330, 340, and 350 (seeFIGS. 24-26) are displays which provide the accurate and up to dateinformation for the system 31. Patient Status Report 330 provides thelocation of the patient by both room and overall grouping. This insuresthat the information to be also tied back to the specific caregivers'responsible for these specific room groupings. The Monitor Status Report340 advises which monitors are available for use within the facility andalso which units are currently in service at the patient bedside.Additional information includes serial number, patient name that is tiedto the DCT and IP address. Other information includes data collectionintervals for each patient. The Room Status Report 350 details patientname, Data Collector Transmitter (DCT) serial number, room number andoverall room grouping.

The Patient Administration Entry Form 360 (see FIG. 27) provides asimple and effective method to enter patient data into the systemrecords of the database 39. Additional information required includesRoom Group, Room Number, turn frequency (default 120 minutes) andallowable turn window (e.g., 15 minutes). Ideally a patient should berotated precisely at the prescribed turn frequency, for example everytwo hours, however, due to actual workload and other demands oncaregiver time; they may not be able to rotate a patient at an exacttime interval. The allowable turn window will provide an additional timerange which allows the caregiver to perform a specified or requiredrotation within a pre-set time interval, for example 15 minutes beyondthe two hour turn frequency. Should a patient remain unturned beyond theestablished turn window interval, the system will “flag” this recordproviding the manager with an indicator that the caregiver has missed aturn. The entry form also allows editing of the patient information inthe event the patient changes rooms or leaves the facility.

The New Bed Monitor Entry Form 370 (see FIG. 28) is intended to allowfacility managers to add new monitor devices to the facility. It alsoallows several selectable functions regarding data transmission viaeither hardwired or wireless link. Other features include assignablequery rate, maximum log intervals, patient info and activation check box(turn on or turn off communication with DCT). This entry form alsoallows editing of existing monitor information.

The Edit Room Groups Form 380 (see FIG. 29) allows easy addition,modification or deletion of specific room groupings. Typically theseroom groups will be tied directly to specific caregiver room assignmentswithin a facility, thus tying the assigned caregiver to their groupingof rooms. Once the room groups are set, only patient rooms fallingwithin these groups will be in the dropdown menu. For example if thereis a “South Room Group” only specific rooms that are pre-assigned duringsetup will be within the dropdown menu. Other rooms within the facilitywill be tied to their proper, pre-determined room group. In addition, afull report may be viewed detailing all room groups within a facility.

The Edit Room Administration Form 390 (see FIG. 30) will allow afacility manager to add, modify or delete rooms within a specific roomgroup. There is also a feature to view the specific rooms and how theyrelate to specific room groups.

Other features such as data export, import, analysis and graphicvisualizations may be considered important in the expansion andenhancement of the system 31.

While the disclosure is susceptible to various modifications andalternative forms, specific exemplary embodiments thereof have beenshown by way of example in the drawings and have herein been describedin detail. It should be understood, however, that there is no intent tolimit the disclosure to the particular forms disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure asdefined by the appended claims.

There is a plurality of advantages of the present invention arising fromthe various features of the subject monitoring system and associatedmethod described herein. It will be noted that alternative embodimentsof the subject monitoring system and associated method of the presentinvention may not include all of the features described yet stillbenefit from at least some of the advantages of such features. Those ofordinary skill in the art may readily devise their own implementationsof a subject monitoring system and associated method that incorporateone or more of the features of the present invention and fall within thespirit and scope of the present invention as defined by the appendedclaims.

What is claimed is:
 1. A system for monitoring a subject, the systemcomprising: a plurality of beds, each bed of said plurality of bedsincluding a data collector transmitter and a sensor array wherein saidsensor array includes a plurality of sensor units; each sensor unit ofsaid plurality of sensor units provides data to said data collectortransmitter wherein the data is transmitted by said data collectortransmitter to a central processor at wide intervals when no movement bythe subject is sensed and the data is transmitted to said centralprocessor at rapid intervals when movement by the subject is sensed,wherein said central processor connects each bed of said plurality ofbeds in a network; a database of said central processor stores the datafrom each bed of said plurality of beds received from said datacollector transmitter, wherein the data includes date data, time data,and position data of the subject within each bed of said plurality ofbeds; said central processor interprets the data to detect a change inposition of the subject within each bed of said plurality of beds andgenerates a report providing caregiver performance data of at least onecaregiver, wherein the caregiver performance data includescaregiver-initiated movement of the subject within each bed of saidplurality of beds in the network.
 2. The system for monitoring a subjectof claim 1, wherein the database further stores a unique address of saiddata collector transmitter and a communication rate of said datacollector transmitter.
 3. The system for monitoring a subject of claim1, wherein the data further includes at least one selected from thegroup of facility, wing, floor, building, and room related to each bedof said plurality of beds.
 4. The system for monitoring a subject ofclaim 1, wherein the position data of the subject is determined by achange in an electrical field of said sensor array.
 5. The system formonitoring a subject of claim 1, wherein said data collector transmitteris wireless.
 6. The system for monitoring a subject of claim 1, whereinthe caregiver performance data further includes a correlation of thecaregiver-initiated movement of a subject relative to that ordered by aphysician.
 7. The system for monitoring a subject of claim 1, whereinthe report further includes a scorecard, and uses a web-based interfacewith visual indicators of overall performance of at least one caregiver.8. The system for monitoring a subject of claim 1, wherein the datacollector transmitter transmits the data of said sensor array to saidcentral processor using at least one protocol selected from the groupcomprising LAN-based data transmission, wireless data transmission,infrared transmission, ZigBee mesh network, Bluetooth™ transmission, andradio frequency transmission.
 9. The system for monitoring a subject ofclaim 1 further comprising a web browser enabled user interface, whereinsaid web browser enabled user interface permits remote access to thereport.
 10. The system for monitoring a subject of claim 1 furthercomprising a notification of caregiver-initiated movement of a subject,wherein said notification is communicated through at least one selectedfrom the group of a pager, a cell phone, an electronic-mail, or afacsimile.
 11. The system for monitoring a subject of claim 1, whereinsaid sensor array is configured to be between said bed and said subjectwhen said subject is on said bed.
 12. The system for monitoring asubject of claim 1, wherein said sensor array comprises soft conductivematerial.
 13. The system for monitoring a subject of claim 1, whereinsaid sensor array is positioned on a mattress pad.